Lower carbon roof tiles incorporate industrial waste

Full-scale manufacturing trials in Australia have shown that incorporating coal ash and glass waste in roof tile production can reduce the carbon footprint of the products.

The manufacturing process replaces 10% of cement with harvested pond ash and 10% of river sand with unwashed glass waste. This takes industrial waste out of the environment and reduces the amount of virgin material needed to produce the tiles, which in turn reduces the energy needed to produce it.

Another of the research team's prototypes—concrete bricks using 15% harvested pond ash and 20% unwashed glass sand—have also proven beneficial while satisfying Australian standards for load-bearing structural concrete and fire performance for wall elements. The waste materials also improve insulation, reducing heat loss by 30% compared to conventional cement bricks.

The coal ash helps enhance concrete performance over time. Tests have shown better dimensional stability, reduced shrinkage cracking, and continued strength gain.